Big-budget sequels lured fans into the megaplexes. The Lord of the Rings: The Return of the King not only dominated the 2003 box office, but it also led the way in Oscar nominations. The Matrix fans were treated to two sequels: Matrix: Reloaded and Revolutions.

Johnny Depp earned a surprise Oscar nomination for his Keith Richards-inspired, swaggering swashbuckler in Pirates of the Caribbean, a Disney special effects extravaganza based on a theme park ride.

The Pixar team released another animated treasure with Finding Nemo, a fish-out-of-water tale about pair of clown fish who brave dark waters and menacing aquatic creatures to be reunited. The film grossed more than $340 million.

The Recording Industry Association of America cracked down on people who illegally swapped more than 1,000 songs over the Internet, filing lawsuits against hundreds of people, including a 12-year-old girl. Apple Computer, however, made downloading both affordable and easy with its iTune Music Store. It allows fans to download tunes for 99 cents each.

Scientists uncover the fossil of a new species of flying dinosaur in northeastern China thought to have existed 120 million years ago. It is the first dinosaur ever found with four wings. The Chinese team that found the dinosaur has named it Microraptor gui, after Chinese paleontologist Gu Zhiwei (Jan. 22).

A joint NASA-Princeton University satellite, the Wilkinson Microwave Anisotropy Probe (WMAP), produced a high-resolution map that captured the oldest light in the universe. It provides some of the most important cosmological discoveries in years. The age of the universe has now been accurately determined as 13.7 billion years old and the birth of stars has been pinpointed to just 200 million years after the Big Bang. The WMAP image also revealed the contents of the universe: only 4% is made up of atoms, or the physical universe as we know it. The remainder is made up of poorly understood substances: dark energy (73%) and dark matter (23%). These findings are consistent with the Big Bang and inflation theories, which assert that the universe materialized in a “big bang” and immediately began cooling and expanding (Feb. 11) .

Three fossilized skulls discovered near the Ethiopian village of Herto in 1997 have now been identified as the oldest known remains of modern humans. Assigned to a new human subspecies called Homo sapiens idaltu (idaltu means elder in the Afar language of Ethiopia), the skulls are estimated to be about 160,000 years olda good 50,000 years older than any previously discovered Homo sapiens (announcement made: June 11).

Scientists publish the first comprehensive analysis of the genetic code of the Y chromosome. The Y chromosome provides just 78 genes out of the estimated 30,000 in human DNA and makes few important contributions beyond determining gender (females have two X chromosomes; males have an X and a Y chromosome). Once the size of the X chromosome, which contains about 1,000 genes, the Y chromosome has been rapidly decaying over the course of human evolution, dwindling to a mere tenth of its former self (June 19).

The Hubble telescope has detected the oldest known planetand it appears to have been formed billions of years earlier than astronomers thought possible. Nicknamed Methuselah after the aged biblical patriarch, the planet is an astonishing 12.7 billion years old (July 10).